There are many laser technologies for laser welding machines, among which laser deep penetration welding is commonly used. There are many factors that affect laser deep penetration welding technology. Understanding and thoroughly understanding these factors will greatly help us improve our welding technology. Next, the Lesser Laser series lists the main factors that affect laser deep penetration welding technology.

laser power

The main factor in laser deep penetration welding is that the laser power simultaneously controls the melting depth and welding speed. The welding melting depth is directly related to the beam power density and is a function of the incident beam power and beam diameter. Generally speaking, as the beam power increases, the melting depth of a certain diameter laser beam will increase.

The diameter of the laser beam



Due to its determination of power density, the size of the beam spot is one of the important variables in laser welding, but for high-power lasers, its measurement is a difficult problem. Usually calculated based on the size of the diffraction spot at the beam focus, but due to the presence of focusing mirror error, the actual spot ratio is larger than the calculated value.





Material absorption rate



There are two factors that affect the absorption of laser beams. Firstly, the resistance coefficient of a material is directly proportional to the square root of the absorption rate of polished surfaces of different materials, and the resistance coefficient varies with temperature. Secondly, the surface state of the material has a significant impact on the absorption of light beams. Therefore, it plays a significant role in the welding effect.





welding speed



The welding speed has a significant impact on the penetration depth. Increasing the speed will make the penetration shallower, but too low a speed can lead to excessive material melting and workpiece welding.

The lens is relatively long



The size of the focus is proportional to the length of the focus. The shorter the length of the focal point, the smaller the spot. But the focal length also affects the depth of focus, which increases synchronously with the focal length, so a short focal length of 126mm is used in many situations.





At the beginning of welding, the laser power at the termination point gradually increases and the control gradually decreases



When laser welding, there will always be small holes regardless of the depth of the weld seam. When the welding process is completed and the power is turned off, pits will appear at the end of the weld seam. In addition, when the laser welding layer covers the original weld seam, the laser beam will be excessively absorbed, leading to overheating or porosity of the welded part.





Protective gas



Inert gases are commonly used for pool protection during laser welding processes. When some materials can be welded without considering surface oxidation, protection is not considered. However, in most applications, argon, nitrogen, and other gases are used as protection to avoid oxidation of the workpiece during the welding process.





The above are the main factors that affect the laser deep penetration welding process, for reference only.